You have a not uncommon departure time for the Middle East and beyond eastwards. Lots of flights from SIN that I've been on have left from 11.30pm to 1.30am.

I'm almost always on business so for me it's usually a 6pm or so finish to the working day, a wrap-up meal with the company I'm visiting and then arrival at the airport around 9pm. It's a bit too long a wait, but not outrageous.

On a tourist visit you'd have even greater flexibility - leave your luggage at the hotel, make the most of the extra time looking round, eat when you like and leave for the airport when you've done all you can. I always find I do more on a last long day than I have in any previous day of a holiday because I'm trying to catch up on all the things I've fallen behind on, so for me there's never enough time!